Techniques and apparatuses for multiple types of physical random access channel (prach) transmission utilization

ABSTRACT

A user equipment (UE) may perform a random access procedure to synchronize with a network for uplink and/or downlink communication. The UE may transmit a first type of random access transmission that includes transmitting a preamble or a second type of random access transmission that includes transmitting a preamble and a random access message. The second type may result in reduced delay but may have lesser SNR tolerance than the first type. In some aspects, the UE may determine whether to transmit the first type or the second type, and may transmit the first type or the second type in a random access channel portion of a slot. The random access channel portion of the slot may be occupied by portions of either the first type of random access transmission or the second type of random access transmission, thereby enabling flexible utilization of multiple types of random access procedure.

CROSS-REFERENCE TO RELATED APPLICATIONS UNDER 35 U.S.C. § 119

This application is a continuation of U.S. patent application Ser. No.15/707,659, filed on Sep. 18, 2017 (now U.S. Pat. No. 10,568,130),entitled “TECHNIQUES AND APPARATUSES FOR MULTIPLE TYPES OF PHYSICALRANDOM ACCESS CHANNEL (PRACH) TRANSMISSION UTILIZATION,” which claimspriority to U.S. Provisional Patent Application 62/438,172 filed on Dec.22, 2016 entitled “TECHNIQUES AND APPARATUSES FOR MULTIPLE TYPES OFPHYSICAL RANDOM ACCESS CHANNEL (PRACH) TRANSMISSION UTILIZATION,” whichare incorporated by reference herein.

BACKGROUND Field

Aspects of the present disclosure generally relate to wirelesscommunication, and more particularly to techniques and apparatuses formultiple types of physical random access channel (PRACH) transmissionutilization.

Background

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, and/or the like). Examples of such multiple-accesstechnologies include code division multiple access (CDMA) systems, timedivision multiple access (TDMA) systems, frequency-division multipleaccess (FDMA) systems, orthogonal frequency-division multiple access(OFDMA) systems, single-carrier frequency-division multiple access(SC-FDMA) systems, time division synchronous code division multipleaccess (TD-SCDMA) systems, and Long Term Evolution (LTE).LTE/LTE-Advanced is a set of enhancements to the Universal MobileTelecommunications System (UMTS) mobile standard promulgated by theThird Generation Partnership Project (3GPP).

A wireless communication network may include a number of base stations(BSs) that can support communication for a number of user equipment(UEs). A UE may communicate with a BS via the downlink and uplink. Thedownlink (or forward link) refers to the communication link from the BSto the UE, and the uplink (or reverse link) refers to the communicationlink from the UE to the BS. As will be described in more detail herein,a BS may be referred to as a Node B, a gNB, an access point (AP), aradio head, a transmit receive point (TRP), a 5G BS, a 5G Node B, and/orthe like.

The above multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless communication devices to communicate on a municipal,national, regional, and even global level. 5G is a set of enhancementsto the LTE mobile standard promulgated by the Third GenerationPartnership Project (3GPP). 5G is designed to better support mobilebroadband Internet access by improving spectral efficiency, loweringcosts, improving services, making use of new spectrum, and betterintegrating with other open standards using OFDM with a cyclic prefix(CP) (CP-OFDM) on the downlink (DL), using CP-OFDM and/or SC-FDM (e.g.,also known as discrete Fourier transform spread ODFM (DFT-s-OFDM)) onthe uplink (UL), as well as supporting beamforming, multiple-inputmultiple-output (MIMO) antenna technology, and carrier aggregation.However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in LTE and 5Gtechnologies. Preferably, these improvements should be applicable toother multiple access technologies and the telecommunication standardsthat employ these technologies.

A user equipment (UE) may perform a random access procedure to obtainaccess to a network for uplink transmission, downlink transmission,and/or the like. To perform the random access procedure, the UE and abase station may exchange messages. For some UEs, the random accessprocedure, such as a physical random access channel (PRACH) randomaccess procedure, may include transmitting multiple messages to the basestation. For example, the UE may transmit a random access transmissionincluding a preamble, may receive a response message from the basestation, may transmit a random access transmission including a randomaccess message, and may receive another response message from the basestation. This may be termed a four-step random access procedure, and theinitial random access transmission may be termed a first type of randomaccess transmission. After completion of the four message random accessprocedure, the UE may be synchronized to perform uplink and/or downlinktransmission.

SUMMARY

The four-step random access procedure may result in excessive delayand/or an excessive amount of network traffic. Thus in 5G, the UE maycombine transmission of the preamble and the random access message intoa single random access transmission, to which the UE may receive asingle response message. This may be termed a two-step random accessprocedure and the random access transmission may be termed a second typeof random access transmission. In this case, the UE may receive thesingle response message after transmitting the second type of randomaccess transmission, and may be synchronized to perform uplink and/ordownlink transmission without another message exchange. In this way, thetwo-step random access procedure reduces delay associated withconnecting to the network.

The two-step random access procedure may necessitate improved channelconditions relative to the four-step random access procedure. Forexample, when the UE transmits the second type of random accesstransmission in a network with relatively poor channel conditions, suchas a signal to noise ratio (SNR) that fails to satisfy a threshold, thesecond type of random access transmission may fail to be received and/ordecoded by the base station. In contrast, the UE may transmit the firsttype of random access transmission when the SNR fails to satisfy thethreshold, and the first type of random access transmission may besuccessfully received and/or decoded as a result of the reduced size offirst type of random access transmission. Thus, it may be beneficial topermit utilization of multiple types of random access transmissionsassociated with multiple types of random access procedures in a networkto account for differing channel conditions.

Aspects described herein may enable utilization of multiple types ofrandom access transmissions (e.g., physical random access channel(PRACH) transmissions) associated with a two-step random accessprocedure, a four-step random access procedure, and/or the like. A firsttype of random access transmission or a second type of random accesstransmission may be utilized based at least in part on, for example,channel conditions of a network. Thus, a likelihood of failure tosynchronize a user equipment (UE) to a network for uplink and/ordownlink when channel conditions are relatively poor is reduced byenabling a first type of random access transmission relative topermitting only the second type of random access transmission under allchannel conditions. Similarly, an amount of time to synchronize the UEto the network when channel conditions are good is reduced by enablingthe second type of random access transmission relative to permittingonly the first type of random access transmission under all channelconditions.

In an aspect of the disclosure, a method, a device, an apparatus, and acomputer program product are provided.

In some aspects, the method may include determining, by a userequipment, whether to transmit at least one of a first type of randomaccess transmission or a second type of random access transmissionwithin a random access channel portion of a slot. The first type ofrandom access transmission may include a preamble. The second type ofrandom access transmission may include the preamble and a random accessmessage. The method may include transmitting, by the user equipment, theat least one of the first type of random access transmission or thesecond type of random access transmission within the random accesschannel portion of the slot.

In some aspects, the device may include a memory and one or moreprocessors coupled to the memory. The memory and the one or moreprocessors may be configured to determine whether to transmit at leastone of a first type of random access transmission or a second type ofrandom access transmission within a random access channel portion of aslot. The first type of random access transmission may include apreamble. The second type of random access transmission may include thepreamble and a random access message. The memory and the one or moreprocessors may be configured to transmit the at least one of the firsttype of random access transmission or the second type of random accesstransmission within the random access channel portion of the slot.

In some aspects, the apparatus may include means for determining whetherto transmit at least one of a first type of random access transmissionor a second type of random access transmission within a random accesschannel portion of a slot. The first type of random access transmissionmay include a preamble. The second type of random access transmissionmay include the preamble and a random access message. The apparatus mayinclude means for transmitting the at least one of the first type ofrandom access transmission or the second type of random accesstransmission within the random access channel portion of the slot.

In some aspects, the computer program product may include anon-transitory computer-readable medium storing one or more instructionsfor wireless communication that, when executed by one or more processorsof a device, cause the one or more processors to determine whether totransmit at least one of a first type of random access transmission or asecond type of random access transmission within a random access channelportion of a slot. The first type of random access transmission mayinclude a preamble. The second type of random access transmission mayinclude the preamble and a random access message. The one or moreinstructions may cause the one or more processors to transmit the atleast one of the first type of random access transmission or the secondtype of random access transmission within the random access channelportion of the slot.

In some aspects, the method may include monitoring for both a first typeof random access transmission and a second type of random accesstransmission within a random access channel portion of a slot, whereinthe first type of random access transmission includes a preamble, andwherein the second type of random access transmission includes thepreamble and a random access message. The method may include receiving,from at least one user equipment, at least one of the first type ofrandom access transmission or the second type of random accesstransmission within the random access channel portion of the slot basedat least in part on monitoring for both the first type of random accesstransmission and the second type of random access transmission.

In some aspects, the device may include a memory and one or moreprocessors coupled to the memory. The memory and the one or moreprocessors may be configured to monitor for both a first type of randomaccess transmission and a second type of random access transmissionwithin a random access channel portion of a slot, wherein the first typeof random access transmission includes a preamble, and wherein thesecond type of random access transmission includes the preamble and arandom access message. The memory and the one or more processors may beconfigured to receive, from at least one user equipment, at least one ofthe first type of random access transmission or the second type ofrandom access transmission within the random access channel portion ofthe slot based at least in part on monitoring for both the first type ofrandom access transmission and the second type of random accesstransmission.

In some aspects, the apparatus may include means for monitoring for botha first type of random access transmission and a second type of randomaccess transmission within a random access channel portion of a slot,wherein the first type of random access transmission includes apreamble, and wherein the second type of random access transmissionincludes the preamble and a random access message. The apparatus mayinclude means for receiving, from at least one user equipment, at leastone of the first type of random access transmission or the second typeof random access transmission within the random access channel portionof the slot based at least in part on monitoring for both the first typeof random access transmission and the second type of random accesstransmission.

In some aspects, the computer program product may include anon-transitory computer-readable medium storing one or more instructionsfor wireless communication that, when executed by one or more processorsof a device, cause the one or more processors to monitor for both afirst type of random access transmission and a second type of randomaccess transmission within a random access channel portion of a slot,wherein the first type of random access transmission includes apreamble, and wherein the second type of random access transmissionincludes the preamble and a random access message. The one or moreinstructions, when executed by the one or more processors, may cause theone or more processors to receive, from at least one user equipment, atleast one of the first type of random access transmission or the secondtype of random access transmission within the random access channelportion of the slot based at least in part on monitoring for both thefirst type of random access transmission and the second type of randomaccess transmission.

Aspects generally include a method, apparatus, system, computer programproduct, non-transitory computer-readable medium, user equipment,wireless communication device, base station, access point, andprocessing system as substantially described herein with reference toand as illustrated by the accompanying drawings.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the scope of the appended claims. Characteristics of theconcepts disclosed herein, both their organization and method ofoperation, together with associated advantages will be better understoodfrom the following description when considered in connection with theaccompanying figures. Each of the figures is provided for the purpose ofillustration and description, and not as a definition of the limits ofthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is diagram) illustrating an example of a wireless communicationnetwork.

FIG. 2 is a diagram illustrating an example of a base station incommunication with a user equipment (UE) in a wireless communicationnetwork.

FIGS. 3A and 3B are diagrams illustrating an example of types of randomaccess transmissions for a random access procedure, such as a physicalrandom access channel (PRACH) procedure.

FIG. 4 is a diagram illustrating an example of a grid of units in anuplink-centric slot for multiple types of random access transmission.

FIGS. 5A-5E are diagrams illustrating examples of resource allocationswithin a grid of units in an uplink-centric slot for multiple types ofrandom access transmission.

FIGS. 6A-6C are diagrams illustrating examples of resource allocationswithin a grid of units in an uplink-centric slot for multiple types ofrandom access transmission.

FIG. 7 is a flow chart of a method of wireless communication.

FIG. 8 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an example apparatus.

FIG. 9 is a diagram illustrating an example of a hardware implementationfor an apparatus employing a processing system.

FIG. 10 is a flow chart of a method of wireless communication.

FIG. 11 is a conceptual data flow diagram illustrating the data flowbetween different modules/means/components in an example apparatus.

FIG. 12 is a diagram illustrating an example of a hardwareimplementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purposes of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well-known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, and/or the like (collectivelyreferred to as “elements”). These elements may be implemented usingelectronic hardware, computer software, or any combination thereof.Whether such elements are implemented as hardware or software dependsupon the particular application and design constraints imposed on theoverall system.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”that includes one or more processors. Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions,and/or the like, whether referred to as software, firmware, middleware,microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions describedmay be implemented in hardware, software, firmware, or any combinationthereof. If implemented in software, the functions may be stored on orencoded as one or more instructions or code on a computer-readablemedium. Computer-readable media includes computer storage media. Storagemedia may be any available media that can be accessed by a computer. Byway of example, and not limitation, such computer-readable media cancomprise a random-access memory (RAM), a read-only memory (ROM), anelectrically erasable programmable ROM (EEPROM), compact disk ROM(CD-ROM) or other optical disk storage, magnetic disk storage or othermagnetic storage devices, combinations of the aforementioned types ofcomputer-readable media, or any other medium that can be used to storecomputer executable code in the form of instructions or data structuresthat can be accessed by a computer.

An access point (“AP”) may comprise, be implemented as, or known as aNodeB, a Radio Network Controller (“RNC”), an eNodeB (eNB), a BaseStation Controller (“BSC”), a Base Transceiver Station (“BTS”), a BaseStation (“BS”), a Transceiver Function (“TF”), a Radio Router, a RadioTransceiver, a Basic Service Set (“BSS”), an Extended Service Set(“ESS”), a Radio Base Station (“RBS”), a Node B (NB), a gNB, a 5G NB, a5G BS, a Transmit Receive Point (TRP), or some other terminology.

An access terminal (“AT”) may comprise, be implemented as, or be knownas an access terminal, a subscriber station, a subscriber unit, a mobilestation, a remote station, a remote terminal, a user terminal, a useragent, a user device, user equipment (UE), a user station, a wirelessnode, or some other terminology. In some aspects, an access terminal maycomprise a cellular telephone, a smart phone, a cordless telephone, aSession Initiation Protocol (“SIP”) phone, a wireless local loop (“WLL”)station, a personal digital assistant (“PDA”), a tablet, a netbook, asmartbook, an ultrabook, a handheld device having wireless connectioncapability, a Station (“STA”), or some other suitable processing deviceconnected to a wireless modem. Accordingly, one or more aspects taughtherein may be incorporated into a phone (e.g., a cellular phone, a smartphone), a computer (e.g., a desktop), a portable communication device, aportable computing device (e.g., a laptop, a personal data assistant, atablet, a netbook, a smartbook, an ultrabook), wearable device (e.g.,smart watch, smart glasses, smart bracelet, smart wristband, smart ring,smart clothing, and/or the like), medical devices or equipment,biometric sensors/devices, an entertainment device (e.g., music device,video device, satellite radio, gaming device, and/or the like), avehicular component or sensor, smart meters/sensors, industrialmanufacturing equipment, a global positioning system device, or anyother suitable device that is configured to communicate via a wirelessor wired medium. In some aspects, the node is a wireless node. Awireless node may provide, for example, connectivity for or to a network(e.g., a wide area network such as the Internet or a cellular network)via a wired or wireless communication link. Some UEs may be consideredmachine-type communication (MTC) UEs, which may include remote devicesthat may communicate with a base station, another remote device, or someother entity. Machine type communications (MTC) may refer tocommunication involving at least one remote device on at least one endof the communication and may include forms of data communication whichinvolve one or more entities that do not necessarily need humaninteraction. MTC UEs may include UEs that are capable of MTCcommunications with MTC servers and/or other MTC devices through PublicLand Mobile Networks (PLMN), for example. Examples of MTC devicesinclude sensors, meters, location tags, monitors, drones, robots/roboticdevices, and/or the like. MTC UEs, as well as other types of UEs, may beimplemented as NB-IoT (narrowband internet of things) devices.

It is noted that while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including 5G technologies.

FIG. 1 is a diagram illustrating a network 100 in which aspects of thepresent disclosure may be practiced. The network 100 may be an LTEnetwork or some other wireless network, such as a 5G network. Wirelessnetwork 100 may include a number of BSs 110 (shown as BS 110 a, BS 110b, BS 110 c, and BS 110 d) and other network entities. A BS is an entitythat communicates with user equipment (UEs) and may also be referred toas a base station, a 5G BS, a Node B, a gNB, a 5G NB, an access point, aTRP, and/or the like. Each BS may provide communication coverage for aparticular geographic area. In 3GPP, the term “cell” can refer to acoverage area of a BS and/or a BS subsystem serving this coverage area,depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or another type of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a closed subscriber group (CSG)). A BS for a macro cell may bereferred to as a macro BS. A BS for a pico cell may be referred to as apico BS. A BS for a femto cell may be referred to as a femto BS or ahome BS. In the example shown in FIG. 1, a BS 110 a may be a macro BSfor a macro cell 102 a, a BS 110 b may be a pico BS for a pico cell 102b, and a BS 110 c may be a femto BS for a femto cell 102 c. A BS maysupport one or multiple (e.g., three) cells. The terms “eNB”, “basestation”, “5G BS”, “gNB”, “TRP”, “AP”, “node B”, “5G NB”, and “cell” maybe used interchangeably herein.

In some examples, a cell may not necessarily be stationary, and thegeographic area of the cell may move according to the location of amobile BS. In some examples, the BSs may be interconnected to oneanother and/or to one or more other BSs or network nodes (not shown) inthe access network 100 through various types of backhaul interfaces suchas a direct physical connection, a virtual network, and/or the likeusing any suitable transport network.

Wireless network 100 may also include relay stations. A relay station isan entity that can receive a transmission of data from an upstreamstation (e.g., a BS or a UE) and send a transmission of the data to adownstream station (e.g., a UE or a BS). A relay station may also be aUE that can relay transmissions for other UEs. In the example shown inFIG. 1, a relay station 110 d may communicate with macro BS 110 a and aUE 120 d in order to facilitate communication between BS 110 a and UE120 d. A relay station may also be referred to as a relay BS, a relaybase station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs ofdifferent types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/orthe like. These different types of BSs may have different transmit powerlevels, different coverage areas, and different impact on interferencein wireless network 100. For example, macro BSs may have a high transmitpower level (e.g., 5 to 40 Watts) whereas pico BSs, femto BSs, and relayBSs may have lower transmit power levels (e.g., 0.1 to 2 Watts).

A network controller 130 may couple to a set of BSs and may providecoordination and control for these BSs. Network controller 130 maycommunicate with the BSs via a backhaul. The BSs may also communicatewith one another, e.g., directly or indirectly via a wireless orwireline backhaul. In some aspects, network controller 130 maycommunicate with the BSs to select a schedule for multiple types ofrandom access transmissions. For example, network controller 130 maydetermine that a first plurality of grid units of a grid of networkresources in a random access channel portion of a slot (e.g., frequencyresources, time resources, cyclic shifts, etc.) is to be allocated for afirst type of random access transmission and a second plurality of gridunits of the grid of network resources in the random access channelportion of the slot is to be allocated for a second type of randomaccess transmission.

UEs 120 (e.g., 120 a, 120 b, 120 c) may be dispersed throughout wirelessnetwork 100, and each UE may be stationary or mobile. A UE may also bereferred to as an access terminal, a terminal, a mobile station, asubscriber unit, a station, and/or the like. A UE may be a cellularphone (e.g., a smart phone), a personal digital assistant (PDA), awireless modem, a wireless communication device, a handheld device, alaptop computer, a cordless phone, a wireless local loop (WLL) station,a tablet, a camera, a gaming device, a netbook, a smartbook, anultrabook, medical device or equipment, biometric sensors/devices,wearable devices (smart watches, smart clothing, smart glasses, smartwrist bands, smart jewelry (e.g., smart ring, smart bracelet)), anentertainment device (e.g., a music or video device, or a satelliteradio), a vehicular component or sensor, smart meters/sensors,industrial manufacturing equipment, a global positioning system device,or any other suitable device that is configured to communicate via awireless or wired medium. Some UEs may be considered evolved or enhancedmachine-type communication (eMTC) UEs. MTC and eMTC UEs include, forexample, robots, drones, remote devices, such as sensors, meters,monitors, location tags, and/or the like, that may communicate with abase station, another device (e.g., remote device), or some otherentity. A wireless node may provide, for example, connectivity for or toa network (e.g., a wide area network such as Internet or a cellularnetwork) via a wired or wireless communication link. Some UEs may beconsidered Internet-of-Things (IoT) devices. Some UEs may be considereda Customer Premises Equipment (CPE).

In FIG. 1, a solid line with double arrows indicates desiredtransmissions between a UE and a serving BS, which is a BS designated toserve the UE on the downlink and/or uplink. A dashed line with doublearrows indicates potentially interfering transmissions between a UE anda BS.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular RAT andmay operate on one or more frequencies. A RAT may also be referred to asa radio technology, an air interface, and/or the like. A frequency mayalso be referred to as a carrier, a frequency channel, and/or the like.Each frequency may support a single RAT in a given geographic area inorder to avoid interference between wireless networks of different RATs.In some cases, 5G RAT networks may be deployed.

In some examples, access to the air interface may be scheduled, whereina scheduling entity (e.g., a base station, a network controller, a userequipment, etc.) allocates resources for communication among some or alldevices and equipment within the scheduling entity's service area orcell. Within the present disclosure, as discussed further below, thescheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. For example, thescheduling entity may schedule an allocation of a grid of units ofnetwork resources for utilization for multiple types of random accesstransmissions. In some aspects, such scheduling information may becommunicated via signaling from the scheduling entity. For example, a UEmay receive a system information block (SIB) message identifying aschedule for the grid of units of network resources, and may perform aparticular type of random access transmission at a particular grid unitof network resources based at least in part on the schedule.

Base stations are not the only entities that may function as ascheduling entity. That is, in some examples, a UE may function as ascheduling entity, scheduling resources for one or more subordinateentities (e.g., one or more other UEs). In this example, the UE isfunctioning as a scheduling entity, and other UEs utilize resourcesscheduled by the UE for wireless communication. A UE may function as ascheduling entity in a peer-to-peer (P2P) network, and/or in a meshnetwork. In a mesh network example, UEs may optionally communicatedirectly with one another in addition to communicating with thescheduling entity.

Thus, in a wireless communication network with a scheduled access totime-frequency resources and having a cellular configuration, a P2Pconfiguration, and a mesh configuration, a scheduling entity and one ormore subordinate entities may communicate utilizing the scheduledresources.

As indicated above, FIG. 1 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 1.

FIG. 2 shows a block diagram 200 of a design of base station 110 and UE120, which may be one of the base stations and one of the UEs in FIG. 1.Base station 110 may be equipped with T antennas 234 a through 234 t,and UE 120 may be equipped with R antennas 252 a through 252 r, where ingeneral T≥1 and R≥1.

At base station 110, a transmit processor 220 may receive data from adata source 212 for one or more UEs, select one or more modulation andcoding schemes (MCS) for each UE based at least in part on channelquality indicators (CQIs) received from the UE, process (e.g., encodeand modulate) the data for each UE based at least in part on the MCS(s)selected for the UE, and provide data symbols for all UEs. Transmitprocessor 220 may also process system information (e.g., for semi-staticresource partitioning information (SRPI), and/or the like) and controlinformation (e.g., CQI requests, grants, upper layer signaling, and/orthe like) and provide overhead symbols and control symbols. Transmitprocessor 220 may also generate reference symbols for reference signals(e.g., the CRS) and synchronization signals (e.g., the primarysynchronization signal (PSS) and secondary synchronization signal(SSS)). A transmit (TX) multiple-input multiple-output (MIMO) processor230 may perform spatial processing (e.g., precoding) on the datasymbols, the control symbols, the overhead symbols, and/or the referencesymbols, if applicable, and may provide T output symbol streams to Tmodulators (MODs) 232 a through 232 t. Each modulator 232 may process arespective output symbol stream (e.g., for OFDM and/or the like) toobtain an output sample stream. Each modulator 232 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. T downlink signals frommodulators 232 a through 232 t may be transmitted via T antennas 234 athrough 234 t, respectively. According to certain aspects described inmore detail below, the synchronization signals can be generated withlocation encoding to convey additional information.

At UE 120, antennas 252 a through 252 r may receive the downlink signalsfrom base station 110 and/or other base stations and may providereceived signals to demodulators (DEMODs) 254 a through 254 r,respectively. Each demodulator 254 may condition (e.g., filter, amplify,downconvert, and digitize) a received signal to obtain input samples.Each demodulator 254 may further process the input samples (e.g., forOFDM and/or the like) to obtain received symbols. A MIMO detector 256may obtain received symbols from all R demodulators 254 a through 254 r,perform MIMO detection on the received symbols if applicable, andprovide detected symbols. A receive processor 258 may process (e.g.,demodulate and decode) the detected symbols, provide decoded data for UE120 to a data sink 260, and provide decoded control information andsystem information to a controller/processor 280. A channel processormay determine RSRP, RSSI, RSRQ, CQI, and/or the like.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data from a data source 262 and control information (e.g., forreports comprising RSRP, RSSI, RSRQ, CQI, and/or the like) fromcontroller/processor 280. Transmit processor 264 may also generatereference symbols for one or more reference signals. The symbols fromtransmit processor 264 may be precoded by a TX MIMO processor 266 ifapplicable, further processed by modulators 254 a through 254 r (e.g.,for DFT-s-OFDM, CP-OFDM, and/or the like), and transmitted to basestation 110. At base station 110, the uplink signals from UE 120 andother UEs may be received by antennas 234, processed by demodulators232, detected by a MIMO detector 236 if applicable, and furtherprocessed by a receive processor 238 to obtain decoded data and controlinformation sent by UE 120. Receive processor 238 may provide thedecoded data to a data sink 239 and the decoded control information tocontroller/processor 240. Base station 110 may include communicationunit 244 and communicate to network controller 130 via communicationunit 244. Network controller 130 may include communication unit 294,controller/processor 290, and memory 292.

Controllers/processors 240 and 280 and/or any other component(s) in FIG.2 may direct the operation at BS 110 and UE 120, respectively, toselectively utilize multiple types of random access transmissions, suchas a first type of random access transmission including a preamble, asecond type of random access transmission including a preamble and arandom access message, and/or the like. For example,controller/processors 240 and 280 and/or other processors and modules atBS 110 or UE 120, respectively, may perform or direct operations of BS110 or UE 120, respectively, to determine whether to use a first type ofrandom access transmission or a second type of random accesstransmission, and to selectively utilize the first type of random accesstransmission or the second type of random access transmission toinitiate a random access procedure. Additionally, or alternatively,controller/processors 240 and 280 and/or other processors and modules atBS 110 or UE 120, respectively, may perform or direct operations of BS110 or UE 120, respectively, to monitor for both a first type of randomaccess transmission and a second type of random access transmissionwithin a random access channel portion of a slot, and to receive atleast one of the first type of random access transmission or the secondtype of random access transmission within the random access channelportion of the slot based at least in part on monitoring for both thefirst type of random access transmission and the second type of randomaccess transmission.

In some aspects, one or more of the components shown in FIG. 2 may beemployed to perform example process 700 of FIG. 7, example process 1000of FIG. 10, and/or other processes for the techniques described herein.Memories 242 and 282 may store data and program codes for BS 110 and UE120, respectively. A scheduler 246 may schedule UEs for datatransmission on the downlink and/or uplink.

As indicated above, FIG. 2 is provided merely as an example. Otherexamples are possible and may differ from what was described with regardto FIG. 2.

FIGS. 3A and 3B are diagrams illustrating an example 300 of types ofrandom access transmissions for a random access procedure, such as aPRACH random access procedure.

As shown in FIG. 3A, a first type of random access transmission mayinclude a preamble and a cyclic prefix. In some aspects, the first typeof random access transmission may be a PRACH random access transmissionfor a four-step PRACH random access procedure. The preamble may includea random access channel (RACH) preamble. The preamble may be used fordetection, timing estimation, and/or the like for the PRACH randomaccess procedure. In some aspects, the cyclic prefix and preamble may bea single unit that can occupy a unit of a grid of units of networkresources of a random access procedure portion of a slot, as describedherein.

As shown in FIG. 3B, a second type of random access transmission mayinclude a set of a preamble and a set of random access messages, eachwith a corresponding cyclic prefix. In some aspects, the second type ofrandom access transmission may be a PRACH random access transmission fora two-step PRACH random access procedure. Each of the preamble and theset of random access messages may be associated with a cyclic prefix.The preamble may be used for detection, timing estimation, ademodulation reference signal (DMRS) for message demodulation, and/orthe like for the PRACH procedure.

The second type of random access transmission may include a first cyclicprefix, a preamble, and at least one pair of a second cyclic prefix anda random access message. In some aspects, the second type of randomaccess transmission may include a plurality of pairs of the second cycleprefix and the random access message. In some aspects, the first cyclicprefix and the preamble may comprise a first unit that can occupy a unitin a grid of units of a random access channel portion of a slot, andeach pair of a second cyclic prefix and a random access message maycomprise a second unit that can occupy another unit in the grid of unitsof the random access channel portion of the slot. In this case, eachunit is associated with respective resources of the random accesschannel portion of the slot (e.g., frequency resources, time resources,cyclic shifts, etc.).

As indicated above, FIGS. 3A and 3B are provided as examples. Otherexamples are possible and may differ from what was described withrespect to FIGS. 3A and 3B.

FIG. 4 is a diagram illustrating an example 400 of a grid of units in anuplink (UL)-centric slot for multiple types of random accesstransmission.

As shown in FIG. 4, example 400 includes a physical downlink controlchannel (PDCCH) portion 402 (PDCCH 402), an uplink long burst (ULLB)portion 404 (ULLB 404), and an uplink short burst (ULSB) portion 406(ULSB 406).

PDCCH 402 is a downlink control portion of the UL-centric slot, and maybe located at a beginning of the UL-centric slot and may be allocated toconvey downlink control information, such as a schedule of a grid ofunits for multiple types of random access transmission.

ULLB 404 is an uplink long burst portion of the UL-centric slot, and maybe located between the PDCCH 402 and the ULSB 406 in the UL-centricslot. The ULLB 404 may sometimes be referred to as the payload of theUL-centric slot. The ULLB 404 may refer to the communication resourcesutilized to communicate UL data from a subordinate entity (e.g., a UE)to a scheduling entity (e.g., a BS). In some aspects, the ULLB 404 maybe used for communications on a physical UL shared channel (PUSCH)and/or a physical uplink control channel (PUCCH).

ULLB 404 may include a random access channel portion 408 of theUL-centric slot and a guard portion 410 of the UL-centric slot. Randomaccess channel portion 408 may include a set of network resources of aUL-centric slot allocated for a random access transmission, such as aPRACH random access transmission. Random access channel portion 408 mayinclude a grid of units 412, such as units 412-1 through 412-N (N≥1).Each unit 412 may be occupied by a portion of at least one of multipletypes of random access transmission. For example, unit 412* may includea cyclic prefix (CP) 414 and a body 416. Body 416 may convey a preamble,a random access message, and/or the like. Thus, unit 412* may convey acyclic prefix and a preamble of the first type of random accesstransmission, a cyclic prefix and a preamble of the second type ofrandom access transmission, a cyclic prefix and a random access messageof the second type of random access transmission, and/or the like. Inthis way, UE 120 may transmit at least one part of the first type ofrandom access transmission or the second type of random accesstransmission in a unit 412 of network resources. In some aspects, aplurality of units 412 may be scheduled for a common user (i.e., asingle UE 120). In some aspects, a first plurality of units 412 may bescheduled for a first user (i.e., a first UE 120) and a second pluralityof units 412 may be scheduled for a second user (i.e., a second UE 120).Guard portion 410 may include a portion of network resources allocatedas a time separation to provide time for switchover from PRACHtransmission in ULLB 404 to another transmission (e.g., PUSCH or PUCCH)in ULSB 406. In some aspects, guard portion 410 may be referred to as agap, a guard interval, and/or various other suitable terms.

ULSB 406 is an uplink short burst portion of the UL-centric slot, andmay be located at the end of a UL-centric slot. ULSB 406 may sometimesbe referred to as a common UL portion, an UL burst, an UL burst portion,a common UL burst, a short burst, an UL short burst, a common UL shortburst, a common UL short burst portion, and/or various other suitableterms. In some aspects, the ULSB 406 may be used for communications on aphysical UL control channel (PUCCH). Additionally, or alternatively, theULSB 406 may be used for communication of uplink control information(UCI), such as a scheduling request (SR), HARQ information (e.g., PUCCHACK, a PUSCH ACK, a PUCCH NACK, a PUSCH NACK, and/or the like), achannel quality indicator (CQI), a channel state indication (CSI), abuffer status report (BSR), a sounding reference signal (SRS), ademodulation reference signal (DMRS), and/or various other suitabletypes of information.

As indicated above, FIG. 4 is provided as an example. Other examples arepossible and may differ from what was described with respect to FIG. 4.

FIGS. 5A-5E are diagrams illustrating an example 500 of resourceallocations within a grid of units in an uplink-centric slot formultiple types of random access transmission.

As shown in FIG. 5A, a resource allocation for random access channelportion 408 of ULLB 404 may be scheduled based at least in part on arepetition level of a random access transmission. The repetition levelmay refer to a number of iterations of the same random accesstransmission that are to be transmitted.

As shown by reference number 502, a first portion of random accesschannel portion 408 (e.g., a first set of units 412) is reserved forlevel 1 repetition of the first type of random access transmission orthe second type of random access transmission. Level 1 repetition mayrefer to a UE 120 transmitting a single iteration of a random accesstransmission. In some aspects, UE 120 may select the number ofrepetitions based at least in part on a set of channel conditions. Forexample, based at least in part on relatively good channel conditions,such as a signal to noise ratio (SNR) satisfying a threshold, a Dopplervalue satisfying a threshold, and/or the like, UE 120 may determine totransmit a single repetition of the random access transmission. Incontrast, when the channel conditions are relatively poor, such as theSNR failing to satisfy a threshold, UE 120 may transmit a plurality ofiterations of the random access transmission.

As shown by reference number 504, a second portion of random accesschannel portion 408 (e.g., a second set of units 412) is reserved forlevel 2 repetition. Level 2 repetition may refer to the UE 120transmitting two iterations of a random access transmission, therebyreducing a likelihood that the random access transmission fails to besuccessfully received and/or decoded by a base station 110. In someaspects, the second portion of random access channel portion 408 and thefirst portion of random access channel portion 408 may use differentresources of the slot. For example, as shown, the first portion and thesecond portion are assigned different frequency and time resources.

As shown by reference number 506, a third portion of random accesschannel portion 408 (e.g., a third set of units 412) is reserved forlevel 3 repetition. Level 3 repetition may refer to the UE 120transmitting three iterations of a random access transmission.Additionally, or alternatively, other levels of repetition may bepossible and may be scheduled in the same or similar portions of randomaccess channel portion 408. In some aspects, a first number ofrepetitions may be selected for a first user of a first UE 120 and asecond number of repetitions may be selected for a second user of asecond UE 120, such as based at least in part on channel conditions,information regarding the first user and/or the second user, and/or thelike. In some aspects, a first number of repetitions may be selectedbased at least in part on a first set of channel conditions and a secondnumber of repetitions may be selected based at least in part on a secondset of channel conditions.

The resources of the slot used for the first set of units 412, thesecond set of units 412, and the third set of units 412, shown in FIG.5A, are provided as examples. Additional, fewer, or different resourcescould be used for the first set of units 412, the second set of units412, and/or the third set of units 412.

As shown in FIG. 5B, unit 508, of a grid of units 412, is reserved forthe first type of random access transmission with level 1 repetition.For example, unit 508 is reserved for cyclic prefix 510 and preamble 512for the first type of random access transmission.

As shown in FIG. 5C, unit 514, of the grid of units 412, is reserved forthe first type of random access transmission with level 2 repetition.For example, unit 514 is reserved for cyclic prefix 516 and preamble 518for the first type of random access transmission.

As further shown, unit 520, of the grid of units 412, is reserved forthe first type of random access transmission with level 2 repetition.For example, unit 520 is reserved for cyclic prefix 522 and preamble524. Cyclic prefix 522 and preamble 524 may be a repetition of cyclicprefix 516 and preamble 518. For example, UE 120 may receive basestation signaling, such as a system information block (SIB), from basestation 110 indicating that unit 514 and unit 520 are reserved forrepetitions of a common random access transmission. This may permit basestation 110 to re-combine random access transmissions of unit 514 andunit 520 to reduce a likelihood of failing to receive the random accesstransmission. In some aspects, UE 120 may frequency hop to transmitmultiple repetitions of a common random access transmission.Additionally, or alternatively, different repetition levels may utilizea common time and/or frequency grid but with different cyclic shifts ofa common root sequence. For example, units 514 and 520 may be disjointin resource allocation of frequency, time, root sequence, cyclic shift,and/or the like, and UE 120 may transmit at a scheduled frequency, time,root sequence, cyclic shift, and/or the like associated with units 514and 520. In this way, UE 120 provides improved SNR tolerance, improvedDoppler tolerance, and/or the like relative to transmitting a singlerandom access transmission via a single frequency.

As shown in FIG. 5D, unit 526, of the grid of units 412, is reserved forthe second type of random access transmission with level 1 repetition.For example, unit 526 is reserved for a cyclic prefix 528 and a preamble530 for the second type of random access transmission.

As further shown, unit 532, of the grid of units 412, is reserved forthe second type of random access transmission with level 1 repetition.For example, unit 532 is reserved for a cyclic prefix 534 and a randomaccess message 536.

As further shown, unit 538, of the grid of units 412, is reserved forthe second type of random access transmission with level 1 repetition.For example, unit 538 is reserved for a cyclic prefix 540 and a randomaccess message 542. In this case, units 526, 532, and 538 may bereserved for a common random access transmission. For example, UE 120may transmit preamble 530 for detection, timing estimation, DMRS, etc.,and may transmit random access messages 536 and 542 to provide a UE-IDparameter, a BSR parameter, and/or the like. In some aspects, units 526,532, and 538 may be reserved for a random access transmissioncorresponding to the second type of random access transmission shown inFIG. 3B.

As shown in FIG. 5E, unit 544, of the grid of units 412, is reserved forthe second type of random access transmission with level 2 repetition.For example, unit 544 is reserved for a cyclic prefix 546 and a preamble548 for the second type of random access transmission.

As further shown, unit 550, of the grid of units 412, is reserved forthe second type of random access transmission with level 2 repetition.For example, unit 550 is reserved for a cyclic prefix 552 and a randomaccess message 554 for the second type of random access transmission.

As further shown, unit 556, of the grid of units 412, is reserved forthe second type of random access transmission with level 2 repetition.For example, unit 556 is reserved for a cyclic prefix 558 and a preamble560 for the second type of random access transmission. In this case,cyclic prefix 558 and preamble 560 of unit 556 are a repetition ofcyclic prefix 546 and preamble 548 of unit 544.

As further shown, unit 562, of the grid of units 412, is reserved forthe second type of random access transmission with level 2 repetition.For example, unit 562 is reserved for a cyclic prefix 564 and a randomaccess message 566 for the second type of random access transmission. Inthis case, cyclic prefix 564 and random access message 566 of unit 562are a repetition of cyclic prefix 552 and random access message 554 ofunit 550. In some aspects, units 544, 550, 556, and 562 may be reservedfor repetitions of a common random access transmission. In some aspects,units 544, 550, 556, and 562 may be reserved for the second type ofrandom access transmission shown in FIG. 3B.

As indicated above, FIGS. 5A-5E are provided as examples. Other examplesare possible and may differ from what was described with respect toFIGS. 5A-5E.

FIGS. 6A-6C are diagrams illustrating an example 600 of resourceallocations within a grid of units in an uplink-centric slot formultiple types of random access transmission.

As shown in FIG. 6A, a first resource allocation may include type Iresource allocations 602-1 and 602-2 and type II resource allocations604-1 and 604-2. Type I resource allocations 602-1 and 602-2 may includeresource allocations (e.g., units 412 of resources associated with oneor more frequencies, times, cyclic shifts, etc.) for the first type ofrandom access transmission shown in FIG. 3A. Type II resourceallocations 604-1 and 604-2 may include resource allocations for thesecond type of random access transmission shown in FIG. 3B. In thiscase, resource allocations for the first type of random accesstransmission and the second type of random access transmission arenon-overlapping (i.e., disjoint) resource allocations. In other words,type I resource allocations 602-1 and 602-2 are associated withdifferent frequencies, different times, and/or different cyclic shifts,within random access channel portion 408 of the uplink-centric slot,than type II resource allocations 604-1 and 604-2.

As shown in FIG. 6B, a second resource allocation may include type Iresource allocations 606-1 and 606-2, type II resource allocation 608,and type I/type II resource allocation 610. Type I resource allocations606-1 and 606-2 may include resource allocations for the first type ofrandom access transmission shown in FIG. 3A. Type II resource allocation608 may include resource allocations for the second type of randomaccess transmission shown in FIG. 3B. Type I/type II resource allocation610 may include a shared resource allocation of units for utilizationfor the first type of random access transmission and/or the second typeof random access transmission. For example, a first UE 120 may utilize aparticular root unit 412 (e.g., a common frequency resource and timeresource) with a first cyclic shift for a cyclic prefix and preamble forthe first type of random access transmission, and a second UE 120 mayutilize the same particular root unit 412 with a second, differentcyclic shift for another cyclic prefix and another preamble for thesecond type of random access transmission. In this case, a base station110 may determine whether the preamble is associated with the first typeof random access transmission or the second type of random accesstransmission, such as based at least in part on the cyclic shift.

As shown in FIG. 6C, a third resource allocation may include type Iresource allocations 612-1 and 612-2, type I/type II resource allocation614, and type I/type II resource allocation 616. Type I resourceallocations 612-1 and 612-2 may include resource allocations for thefirst type of random access transmission shown in FIG. 3A. Type I/typeII resource allocation 614 may include a shared resource allocation ofunits for utilization for a preamble of the first type of random accesstransmission and/or a preamble of the second type of random accesstransmission. Type I/type II resource allocation 616 may include ashared resource allocation of units for utilization for a preamble ofthe first type of random access transmission and/or a random accessmessage for the second type of random access transmission. In someaspects, type I/type II resource allocation 614 may be utilized for thefirst type of random access transmission with a first cyclic shiftand/or the second type of random access transmission with a second,different cyclic shift. In this case, UE 120 may transmit either apreamble of the first type of random access transmission using units 412of type I/type II resource allocation 616 or a random access message ofthe second type of random access transmission using units 412 of typeI/type II resource allocation 616, and a base station 110 may detectwhether UE 120 transmitted a preamble of the first type of random accessmessage, a preamble of the second type of random access message or oneor more of a set of random access messages.

As indicated above, FIGS. 6A-6C are provided as examples. Other examplesare possible and may differ from what was described with respect toFIGS. 6A-6C.

FIG. 7 is a flow chart of a method 700 of wireless communication. Themethod 700 may be performed by a UE (e.g., which may correspond to oneor more of the UE 120, the apparatus 800/800′, user equipment 1150,and/or the like).

At 710, in some aspects, the UE receives base station signalingidentifying a schedule for resources of a random access channel portionof a slot (block 710). For example, a first type of random accesstransmission may be scheduled for first resources of the random accesschannel portion of the slot and a second type of random accesstransmission may be scheduled for second resources of the random accesschannel portion of the slot. In some aspects, the first resources may beseparate from the second resources.

At 720, the UE determines whether to transmit at least one of a firsttype of random access transmission or a second type of random accesstransmission within the random access channel portion of the slot (block720). For example, the UE may determine whether to transmit the at leastone of the first type of random access transmission or the second typeof random access transmission within the random access channel portionof the slot. In this case, the UE may determine whether to transmit thefirst type of random access transmission or the second type of randomaccess transmission based at least in part on channel conditions, suchas an SNR parameter, a Doppler parameter, and/or the like. In someaspects, the first type of random access transmission includes apreamble. In some aspects, the second type of random access transmissionincludes the preamble and a random access message.

In some aspects, the first type of random access transmission and thesecond type of random access transmission are each comprised of a commonunit structure, the random access channel portion of the slot comprisesa grid of units, and the preamble occupies one unit, of the grid ofunits, and the random access message occupies one unit of the grid ofunits. In some aspects, the second type of random access transmissionincludes a plurality of random access messages and each of the pluralityof random access messages occupies a different unit of the grid ofunits.

In some aspects, the slot includes a downlink control portion, an uplinklong burst portion, and an uplink short burst portion and the randomaccess channel portion is configured within the uplink long burstportion. In some aspects, the first type of random access transmissionis a first type of physical random access channel (PRACH) random accesstransmission, the second type of random access transmission is a secondtype of PRACH random access transmission, the preamble of the first typeof PRACH random access transmission is a first random access channel(RACH) preamble, the preamble of the second type of PRACH random accesstransmission is a second RACH preamble, and the random access message isa RACH random access message.

At 730, the UE transmits the at least one of the first type of randomaccess transmission or the second type of random access transmissionwithin the random access channel portion of the slot (block 730). Forexample, the UE may transmit the at least one of the first type ofrandom access transmission or the second type of random accesstransmission within the random access channel portion of the slot. Inthis case, the UE may transmit the first type of random accesstransmission or the second type of random access transmission to a basestation to initiate a random access procedure, such as a physical randomaccess channel (PRACH) random access procedure. Based at least in parton completing the random access procedure, the UE may be synchronizedfor uplink transmission and/or downlink transmission.

In some aspects, the first type of random access transmission and thesecond type of random access transmission are transmitted within therandom access channel portion of the slot. In some aspects, the firsttype of random access transmission and the second type of random accesstransmission are transmitted using separate resources of the randomaccess channel portion of the slot. In some aspects, a schedule for theseparate resources is identified by base station signaling. In someaspects, the first type of random access transmission and the secondtype of random access transmission share at least one resource of therandom access channel portion of the slot. In some aspects, the at leastone resource is associated with a first cyclic shift for the first typeof random access transmission and a second cyclic shift for the secondtype of random access transmission.

In some aspects, the at least one of the first type of random accesstransmission or the second type of random access transmission istransmitted for a number of repetitions within the random access channelportion of the slot. In some aspects, the number of repetitions isselected based at least in part on a set of channel conditions. In someaspects, the number of repetitions uses different resources of therandom access channel portion of the slot. In some aspects, thedifferent resources include at least one of different frequencies,different times, or different cyclic shifts within the random accesschannel portion of the slot. In some aspects, a schedule for thedifferent resources, of the random access channel portion of the slot,is identified by base station signaling. In some aspects, a first numberof repetitions is associated with a first user and a second number ofrepetitions is associated with a second user.

Although FIG. 7 shows example blocks of a method of wirelesscommunication, in some aspects, the method may include additionalblocks, fewer blocks, different blocks, or differently arranged blocksthan those shown in FIG. 7. Additionally, or alternatively, two or moreblocks shown in FIG. 7 may be performed in parallel.

FIG. 8 is a conceptual data flow diagram 800 illustrating the data flowbetween different modules/means/components in an example apparatus 802.The apparatus 802 may be a UE. In some aspects, the apparatus 802includes a reception module 804, a determining module 806, and/or atransmission module 808.

The reception module 804 may receive, from a base station 850 and asdata 810, one or more signaling messages, one or more networkmeasurements, and/or the like. The one or more signaling messages mayinclude one or more SIBs that may identify a resource allocation for arandom access channel portion of a slot. The one or more signalingmessages may identify a portion of the resource allocation reserved fora first type of random access transmission that includes a preamble, asecond type of random access transmission that includes a preamble and arandom access message, and/or the like. The random access channelportion of the slot may include a grid of units, and each unit may beallocatable to use for the preamble of the first type of random accesstransmission, the preamble of the second type of random accesstransmission, the random access message of the second type of randomaccess transmission, and/or the like.

The determining module 806 may receive, from reception module 804 and asdata 812, information indicating whether to transmit at least one of thefirst type of random access transmission or the second type of randomaccess transmission. For example, based at least in part on a networkmeasurement indicating a threshold SNR value, the determining module 806may determine to transmit the second type of random access transmission.Alternatively, based at least in part on the network measurementindicating that the SNR value does not satisfy the threshold, thedetermining module 806 may determine to transmit the first type ofrandom access transmission. In some aspects, the determining module 806may determine a level of repetitions for the random access transmission,a set of units of a resource grid representing a set of allocatableresources to utilize to transmit the random access transmission, and/orthe like.

The transmission module 808 may receive, from the determining module 806and as data 814, information indicating whether to transmit the at leastone of the first type of random access transmission or the second typeof random access transmission within the random access channel portionof the slot based at least in part on the determining module 806performing the determining. The transmission module 808 may transmit, tobase station 850 and as data 816, the at least one of the first type ofrandom access transmission or the second type of random accesstransmission within the random access channel portion of the slot basedat least in part on receiving data 814.

The apparatus may include additional modules that perform each of theblocks of the algorithm in the aforementioned flow chart of FIG. 7. Assuch, each block in the aforementioned flow chart of FIG. 7 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

The number and arrangement of modules shown in FIG. 8 are provided as anexample. In practice, there may be additional modules, fewer modules,different modules, or differently arranged modules than those shown inFIG. 8. Furthermore, two or more modules shown in FIG. 8 may beimplemented within a single module, or a single module shown in FIG. 8may be implemented as multiple, distributed modules. Additionally, oralternatively, a set of modules (e.g., one or more modules) shown inFIG. 8 may perform one or more functions described as being performed byanother set of modules shown in FIG. 8.

FIG. 9 is a diagram 900 illustrating an example of a hardwareimplementation for an apparatus 802′ employing a processing system 902.The apparatus 802′ may be a UE.

The processing system 902 may be implemented with a bus architecture,represented generally by the bus 904. The bus 904 may include any numberof interconnecting buses and bridges depending on the specificapplication of the processing system 902 and the overall designconstraints. The bus 904 links together various circuits including oneor more processors and/or hardware modules, represented by the processor906, the modules 804, 806, 808, and the computer-readable medium/memory908. The bus 904 may also link various other circuits such as timingsources, peripherals, voltage regulators, and power management circuits,which are well known in the art, and therefore, will not be describedany further.

The processing system 902 may be coupled to a transceiver 910. Thetransceiver 910 is coupled to one or more antennas 912. The transceiver910 provides a means for communicating with various other apparatus overa transmission medium. The transceiver 910 receives a signal from theone or more antennas 912, extracts information from the received signal,and provides the extracted information to the processing system 902,specifically the reception module 804. In addition, the transceiver 910receives information from the processing system 902, specifically thetransmission module 808, and based at least in part on the receivedinformation, generates a signal to be applied to the one or moreantennas 912. The processing system 902 includes a processor 906 coupledto a computer-readable medium/memory 908. The processor 906 isresponsible for general processing, including the execution of softwarestored on the computer-readable medium/memory 908. The software, whenexecuted by the processor 906, causes the processing system 902 toperform the various functions described supra for any particularapparatus. The computer-readable medium/memory 908 may also be used forstoring data that is manipulated by the processor 906 when executingsoftware. The processing system further includes at least one of themodules 804, 806, and 808. The modules may be software modules runningin the processor 906, resident/stored in the computer readablemedium/memory 908, one or more hardware modules coupled to the processor906, or some combination thereof. The processing system 902 may be acomponent of the UE 120 and may include the memory 282 and/or at leastone of the TX MIMO processor 266, the RX processor 258, and/or thecontroller/processor 280.

In some aspects, the apparatus 802/802′ for wireless communicationincludes means for determining whether to transmit at least one of afirst type of random access transmission or a second type of randomaccess transmission within a random access channel portion of a slot. Insome aspects, the apparatus 802/802′ for wireless communication includesmeans for transmitting the at least one of the first type of randomaccess transmission or the second type of random access transmissionwithin the random access channel portion of the slot. The aforementionedmeans may be one or more of the aforementioned modules of the apparatus802 and/or the processing system 902 of the apparatus 802′ configured toperform the functions recited by the aforementioned means. As describedsupra, the processing system 902 may include the TX MIMO processor 266,the RX processor 258, and/or the controller/processor 280. As such, inone configuration, the aforementioned means may be the TX MIMO processor266, the RX processor 258, and/or the controller/processor 280configured to perform the functions recited by the aforementioned means.

FIG. 9 is provided as an example. Other examples are possible and maydiffer from what was described in connection with FIG. 9.

FIG. 10 is a flow chart of a method 1000 of wireless communication. Themethod 1000 may be performed by a BS (e.g., which may correspond to oneor more of the BS 110, the base station 850, the apparatus 1100/1100′,and/or the like).

At 1010, in some aspects, the BS provides base station signalingidentifying a schedule for resources of a random access channel portionof a slot (block 1010). For example, a first type of random accesstransmission may be scheduled for first resources of the random accesschannel portion of the slot and a second type of random accesstransmission may be scheduled for second resources of the random accesschannel portion of the slot. In some aspects, the first resources may beseparate from the second resources.

At 1020, the BS monitors for both a first type of random accesstransmission and a second type of random access transmission within therandom access channel portion of the slot (block 1020). For example, theBS may monitor for the first type of random access transmission, whichmay include a preamble, and the second type of random accesstransmission, which may include a preamble and a random access message,to enable a user equipment (e.g., UE 120, the apparatus 800/800′, userequipment 1150, and/or the like) to transmit at least one of the firsttype of random access transmission or the second type of random accesstransmission.

In some aspects, the first type of random access transmission and thesecond type of random access transmission are each comprised of a commonunit structure, the random access channel portion of the slot comprisesa grid of units, and the preamble occupies one unit, of the grid ofunits, and the random access message occupies one unit of the grid ofunits. In some aspects, the second type of random access transmissionincludes a plurality of random access messages, and each of theplurality of random access messages occupies a different unit of thegrid of units. In some aspects, the first type of random accesstransmission and the second type of random access transmission arereceived within the random access channel portion of the slot.

In some aspects, the first type of random access transmission and thesecond type of random access transmission are received using separateresources of the random access channel portion of the slot. In someaspects, a schedule for the separate resources is identified by basestation signaling. In some aspects, the first type of random accesstransmission and the second type of random access transmission share atleast one resource of the random access channel portion of the slot. Insome aspects, the at least one resource is associated with a firstcyclic shift for the first type of random access transmission and asecond cyclic shift for the second type of random access transmission.

At 1030, the BS receives, from at least one user equipment, at least oneof the first type of random access transmission or the second type ofrandom access transmission within the random access channel portion ofthe slot based at least in part on monitoring for both the first type ofrandom access transmission and the second type of random accesstransmission (block 1030). For example, the BS may receive the firsttype of random access transmission based at least in part on monitoringfor both the first type of random access transmission and the secondtype of random access transmission. Additionally, or alternatively, theBS may receive the second type of random access transmission based atleast in part on monitoring for both the first type of random accesstransmission and the second type of random access transmission.Additionally, or alternatively, the BS may receive both the first typeof random access transmission and the second type of random accesstransmission based at least in part on monitoring for both the firsttype of random access transmission and the second type of random accesstransmission.

Although FIG. 10 shows example blocks of a method of wirelesscommunication, in some aspects, the method may include additionalblocks, fewer blocks, different blocks, or differently arranged blocksthan those shown in FIG. 10. Additionally, or alternatively, two or moreblocks shown in FIG. 10 may be performed in parallel.

FIG. 11 is a conceptual data flow diagram 1100 illustrating the dataflow between different modules/means/components in an example apparatus1102. The apparatus 1102 may be a BS. In some aspects, the apparatus1102 includes a reception module 1104, a monitoring module 1106, and/ora transmission module 1108.

The reception module 1104 may receive, from a user equipment 1150 and asdata 1110 and/or data 1112, information identifying a random accesstransmission. For example, based at least in part on the monitoringmodule 1106 indicating that the reception module 1104 is to monitor forboth a first type of random access transmission and a second type ofrandom access transmission within a random access channel portion of aslot, the reception module 1104 may receive at least one of the firsttype of random access transmission or the second type of random accesstransmission within the random access channel portion of the slot.

The monitoring module 1106 may receive, from the reception module 1104and as data 1114, information associated with a random accesstransmission. For example, the monitoring module 1106 may receive anacknowledgement message from the user equipment 1150 indicating anacknowledgement of a schedule for random access transmissions providedby the transmission module 1108. In some aspects, the first type ofrandom access transmission and the second type of random accesstransmission may be scheduled for separate resources of the randomaccess channel portion of the slot.

The transmission module 1108 may receive, from the monitoring module1106 and as data 1116, information associated with a random accesstransmission. For example, the transmission module 1108 may receiveinformation indicating receipt of a random access transmission by thereception module 1104 based at least in part on the monitoring module1106 causing the reception module 1104 to receive the random accesstransmission. In this case, the transmission module 1108 may providedata 1118 to user equipment 1150 to acknowledge receipt of the firsttype of random access transmission or the second type of random accesstransmission. Additionally or alternatively, the transmission module1108 may provide base station signaling identifying a schedule for theuser equipment 1150 to use to transmit at least one of the first type ofrandom access transmission or the second type of random accesstransmission.

The apparatus may include additional modules that perform each of theblocks of the algorithm in the aforementioned flow chart of FIG. 10. Assuch, each block in the aforementioned flow chart of FIG. 10 may beperformed by a module and the apparatus may include one or more of thosemodules. The modules may be one or more hardware components specificallyconfigured to carry out the stated processes/algorithm, implemented by aprocessor configured to perform the stated processes/algorithm, storedwithin a computer-readable medium for implementation by a processor, orsome combination thereof.

The number and arrangement of modules shown in FIG. 11 are provided asan example. In practice, there may be additional modules, fewer modules,different modules, or differently arranged modules than those shown inFIG. 11. Furthermore, two or more modules shown in FIG. 11 may beimplemented within a single module, or a single module shown in FIG. 11may be implemented as multiple, distributed modules. Additionally, oralternatively, a set of modules (e.g., one or more modules) shown inFIG. 11 may perform one or more functions described as being performedby another set of modules shown in FIG. 11.

FIG. 12 is a diagram 1200 illustrating an example of a hardwareimplementation for an apparatus 1102′ employing a processing system1202. The apparatus 1102′ may be a BS.

The processing system 1202 may be implemented with a bus architecture,represented generally by the bus 1204. The bus 1204 may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system 1202 and the overall designconstraints. The bus 1204 links together various circuits including oneor more processors and/or hardware modules, represented by the processor1206, the modules 1104, 1106, 1108, and the computer-readablemedium/memory 1208. The bus 1204 may also link various other circuitssuch as timing sources, peripherals, voltage regulators, and powermanagement circuits, which are well known in the art, and therefore,will not be described any further.

The processing system 1202 may be coupled to a transceiver 1210. Thetransceiver 1210 is coupled to one or more antennas 1212. Thetransceiver 1210 provides a means for communicating with various otherapparatus over a transmission medium. The transceiver 1210 receives asignal from the one or more antennas 1212, extracts information from thereceived signal, and provides the extracted information to theprocessing system 1202, specifically the reception module 1104. Inaddition, the transceiver 1210 receives information from the processingsystem 1202, specifically the transmission module 1108, and based atleast in part on the received information, generates a signal to beapplied to the one or more antennas 1212. The processing system 1202includes a processor 1206 coupled to a computer-readable medium/memory1208. The processor 1206 is responsible for general processing,including the execution of software stored on the computer-readablemedium/memory 1208. The software, when executed by the processor 1206,causes the processing system 1202 to perform the various functionsdescribed supra for any particular apparatus. The computer-readablemedium/memory 1208 may also be used for storing data that is manipulatedby the processor 1206 when executing software. The processing systemfurther includes at least one of the modules 1104, 1106, and 1108. Themodules may be software modules running in the processor 1206,resident/stored in the computer readable medium/memory 1208, one or morehardware modules coupled to the processor 1206, or some combinationthereof. The processing system 1202 may be a component of the BS 110 andmay include the memory 242 and/or at least one of the TX MIMO processor230, the RX processor 238, and/or the controller/processor 240.

In some aspects, the apparatus 1102/1102′ for wireless communicationincludes means for monitoring for both a first type of random accesstransmission and a second type of random access transmission within arandom access channel portion of a slot. In some aspects, the apparatus1102/1102′ for wireless communication includes means for receiving, fromat least one user equipment, at least one of the first type of randomaccess transmission or the second type of random access transmissionwithin the random access channel portion of the slot based at least inpart on monitoring for both the first type of random access transmissionand the second type of random access transmission. The aforementionedmeans may be one or more of the aforementioned modules of the apparatus1102 and/or the processing system 1202 of the apparatus 1102′ configuredto perform the functions recited by the aforementioned means. Asdescribed supra, the processing system 1202 may include the TX MIMOprocessor 230, the RX processor 238, and/or the controller/processor240. As such, in one configuration, the aforementioned means may be theTX MIMO processor 230, the RX processor 238, and/or thecontroller/processor 240 configured to perform the functions recited bythe aforementioned means.

FIG. 12 is provided as an example. Other examples are possible and maydiffer from what was described in connection with FIG. 12.

It is understood that the specific order or hierarchy of blocks in theprocesses/flow charts disclosed is an illustration of exampleapproaches. Based upon design preferences, it is understood that thespecific order or hierarchy of blocks in the processes/flow charts maybe rearranged. Further, some blocks may be combined or omitted. Theaccompanying method claims present elements of the various blocks in asample order, and are not meant to be limited to the specific order orhierarchy presented.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” The word “exemplary” is used hereinto mean “serving as an example, instance, or illustration.” Any aspectdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects. Unless specifically statedotherwise, the term “some” refers to one or more. Combinations such as“at least one of A, B, or C,” “at least one of A, B, and C,” and “A, B,C, or any combination thereof” include any combination of A, B, and/orC, and may include multiples of A, multiples of B, or multiples of C.Specifically, combinations such as “at least one of A, B, or C,” “atleast one of A, B, and C,” and “A, B, C, or any combination thereof” maybe A only, B only, C only, A and B, A and C, B and C, or A and B and C,where any such combinations may contain one or more member or members ofA, B, or C. All structural and functional equivalents to the elements ofthe various aspects described throughout this disclosure that are knownor later come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed as a means plus function unless the element is expresslyrecited using the phrase “means for.”

What is claimed is:
 1. A method for wireless communication, comprising:determining, by a user equipment, whether to transmit at least one of afirst type of random access transmission or a second type of randomaccess transmission within a random access channel portion of a slot,wherein the first type of random access transmission includes apreamble, wherein the second type of random access transmission includesthe preamble and a random access message; and transmitting, by the userequipment, the at least one of the first type of random accesstransmission or the second type of random access transmission within therandom access channel portion of the slot.
 2. The method of claim 1,wherein the first type of random access transmission and the second typeof random access transmission are each comprised of a common unitstructure; wherein the random access channel portion of the slotcomprises a grid of units; and wherein the preamble occupies one unit,of the grid of units, and the random access message occupies one unit ofthe grid of units.
 3. The method of claim 2, wherein the second type ofrandom access transmission includes a plurality of random accessmessages; and wherein each of the plurality of random access messagesoccupies a different unit of the grid of units.
 4. The method of claim1, wherein the first type of random access transmission and the secondtype of random access transmission are transmitted within the randomaccess channel portion of the slot.
 5. The method of claim 4, whereinthe first type of random access transmission and the second type ofrandom access transmission are transmitted using separate resources ofthe random access channel portion of the slot.
 6. The method of claim 5,wherein a schedule for the separate resources is identified by basestation signaling.
 7. The method of claim 4, wherein the first type ofrandom access transmission and the second type of random accesstransmission share at least one resource of the random access channelportion of the slot.
 8. The method of claim 7, wherein the at least oneresource is associated with a first cyclic shift for the first type ofrandom access transmission and a second cyclic shift for the second typeof random access transmission.
 9. The method of claim 1, wherein the atleast one of the first type of random access transmission or the secondtype of random access transmission is transmitted for a number ofrepetitions within the random access channel portion of the slot. 10.The method of claim 9, wherein the number of repetitions is selectedbased at least in part on a set of channel conditions.
 11. The method ofclaim 9, wherein the number of repetitions uses different resources ofthe random access channel portion of the slot.
 12. The method of claim11, wherein the different resources include at least one of differentfrequencies, different times, or different cyclic shifts within therandom access channel portion of the slot.
 13. The method of claim 11,wherein a schedule for the different resources, of the random accesschannel portion of the slot, is identified by base station signaling.14. The method of claim 9, wherein a first number of repetitions isassociated with a first user and a second number of repetitions isassociated with a second user.
 15. The method of claim 1, wherein theslot includes a downlink control portion, an uplink long burst portion,and an uplink short burst portion, wherein the random access channelportion is configured within the uplink long burst portion.
 16. Themethod of claim 1, wherein the first type of random access transmissionis a first type of physical random access channel (PRACH) random accesstransmission, wherein the second type of random access transmission is asecond type of PRACH random access transmission, wherein the preamble ofthe first type of PRACH random access transmission is a first randomaccess channel (RACH) preamble, wherein the preamble of the second typeof PRACH random access transmission is a second RACH preamble, andwherein the random access message is a RACH random access message.
 17. Adevice for wireless communication, comprising: memory; and one or moreprocessors coupled to the memory, the memory and the one or moreprocessors configured to: determine whether to transmit at least one ofa first type of random access transmission or a second type of randomaccess transmission within a random access channel portion of a slot,wherein the first type of random access transmission includes apreamble, wherein the second type of random access transmission includesthe preamble and a random access message; and transmit the at least oneof the first type of random access transmission or the second type ofrandom access transmission within the random access channel portion ofthe slot.
 18. The device of claim 17, wherein the first type of randomaccess transmission and the second type of random access transmissionare each comprised of a common unit structure; wherein the random accesschannel portion of the slot comprises a grid of units; and wherein thepreamble occupies one unit, of the grid of units, and the random accessmessage occupies one unit of the grid of units.
 19. The device of claim18, wherein the second type of random access transmission includes aplurality of random access messages; and wherein each of the pluralityof random access messages occupies a different unit of the grid ofunits.
 20. The device of claim 17, wherein the first type of randomaccess transmission and the second type of random access transmissionare transmitted within the random access channel portion of the slot.